Note 9 - Income Taxes - Reconciliation of Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2021	Dec. 26, 2020	Dec. 28, 2019
Balance at beginning of year	$ 33,696	$ 34,740	$ 34,873
Additions for tax positions of current year	686	817	1,231
Reductions for tax positions of prior years	(83)	(425)	(484)
Reductions due to lapse of the statute of limitations	(1,012)	(304)	(957)
Reductions due to settlements	0	(1,134)	(30)
Foreign exchange rate impact	104	2	107
Balance at end of year	$ 33,391	$ 33,696	$ 34,740